Issue loading rxjs bundle with SystemJs

Versions

npm: 3.10.9
systemjs: 0.19.41
typescript: 1.8.10
rxjs: 5.0.3

Background

I have a project (that's written in typescript) that i'm trying to add rxjs to, but have come across an issue when loading the bundled file through systemjs.

SystemJs config

System.config({
    transpiler: 'typescript',
    paths: {
        'src:*': '/src/*',
        'npm:*': '/node_modules/*'
    },
    map: {
        'lib': 'src:lib',
        'rxjs': 'npm:rxjs/bundles/Rx.js',
        'typescript': 'npm:typescript/lib/typescript.js',
        'systemjs': 'npm:systemjs/dist/system.src.js'
    },
    packages: {
        lib: {
            defaultExtension: 'js'
        }
    }
});

Problem

Using the above config, i get the following error.

Error: (SystemJS) undefined is not a constructor (evaluating '__extends(UnsubscriptionError, _super)')

Which is caused by the fact that systemjs incorrectly defaults to amd format and the exporter function on line 245 of Rx.js never gets executed.

From the systemjs docs:

Module format detection

When the module format is not set, automatic regular-expression-based detection is used. This module format detection is never completely accurate, but caters well for the majority use cases.

Attempted solution

I presumed that explicitly setting the rxjs package format to global in the config would fix this issue.

System.config({
    transpiler: 'typescript',
    paths: {
        'src:*': '/src/*',
        'npm:*': '/node_modules/*'
    },
    map: {
        'lib': 'src:lib',
        'rxjs': 'npm:rxjs/bundles/Rx.js',
        'typescript': 'npm:typescript/lib/typescript.js',
        'systemjs': 'npm:systemjs/dist/system.src.js'
    },
    packages: {
        lib: {
            defaultExtension: 'js'
        },
        rxjs: {
            format: 'global'
        }
    }
});

Problem 2

Although this fixed the first issue, it created a second. As everywhere that i attempt to use the rxjs imports now throws an error, as they're undefined.

import {Observable} from 'rxjs'

export class SomeClass {

    ...
    
    private _isObservable(arg: any): boolean {
        return arg instanceof Observable;
    }
}

Uncaught TypeError: Right-hand side of 'instanceof' is not an object at SomeClass._isObservable

Debugging the transpiled code in the console reveals that although window.Rx gets correctly set to the Rx object, the rxjs_1_1 object that gets set on SomeClass, is not the global Rx object, but instead another object with the Rx global set as a property 'Rx' on it.

So rxjs_1.Rx.Observable works, but not of rxjs_1.Observable`.

(function(System, SystemJS) {System.register(['rxjs'], function(exports_1, context_1) {
"use strict";
var __moduleName = context_1 && context_1.id;
var rxjs_1;
var SomeClass;
return {
    setters:[
        function (rxjs_1_1) {
            rxjs_1 = rxjs_1_1;
        }],
    execute: function() {
        SomeClass = (function () {
            function SomeClass() {
            }
            ...
            SomeClass.prototype._isObservable = function (arg) {
                return arg instanceof rxjs_1.Observable;
            };
            return SomeClass;
        }());
        exports_1("SomeClass", SomeClass);
    }
}

});

Question

Any idea how i get it to pass in Rx object instead?